


REALITALE

by AnimeTrashcan



Category: Undertale (Video Game)
Genre: Aged-Up Frisk (Undertale), Alternate Universe, Alternate Universe - Original, Dreams vs. Reality, F/F, F/M, Female Frisk (Undertale), Frisk (Undertale) Has PTSD - Post-Traumatic Stress Disorder, Frisk (Undertale) Is a Sweetheart, Other Additional Tags to Be Added, Pacifist Frisk (Undertale), Post-Traumatic Stress Disorder - PTSD, Post-Undertale Genocide Route, Protective Sans (Undertale), Sans (Undertale) Has PTSD - Post-Traumatic Stress Disorder, Undertale Spoilers
Language: English
Status: In-Progress
Published: 2020-03-11
Updated: 2020-03-13
Packaged: 2021-03-01 02:49:13
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings, Graphic Depictions Of Violence, Major Character Death
Chapters: 2
Words: 3,830
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23108008
Author URL: https://archiveofourown.org/users/AnimeTrashcan/pseuds/AnimeTrashcan
Summary: Undertale… the friendly RPG where nobody has to die!A cool new video game just came out, and it’s the only thing everyone’s talking about!  All young 12- year-old Krista hears about these days is Undertale this, Undertale that… what kind of game is this?  She decides to try it out… and she absolutely loves it!  But, things start to become wonky ever since she tried out that cool new game.Every night it seems her dreams are flashbacks, and the people closest to her are… glitching out?  Headaches seem to happen all the time now… what’s going on?  It’s like the world she knew is falling apart.Or maybe…The world she knew was never real…?
Relationships: Alphys/Undyne (Undertale), Frisk/Sans (Undertale), Other Relationship Tags to Be Added
Comments: 2
Kudos: 3





	1. PROULOGUE

**Author's Note:**

> Hey readers! This is my first EVER work here on Ao3. I'm really excited to put this out there because one, I've been working on this since 2019, and two, I'm a HUGE fan of Undertale as you can already guess. I stopped working on it back in 2019 because I realized there was literally no reason to write this. I mean, I wasn't even going to post it because I'm really self-conscious about my writing. I also had a big misconception about Fan Fiction. When I hear fan-fic, I think of smut, fluff, and sexualizing beloved characters. Don't get me wrong, it's not like I'm not into that stuff. ( ͡° ͜ʖ ͡°) But that just got to me and I never really wanted to write about it. I'm a huge fantasy writer, and have done many written practices in my own time, and have always had a fondness for literature in general. So, this is sort of like my own take on UNDERTALE, and how cool it would be to realize that the reality you were living in was a dream, and UNDERTALE was the true reality. 
> 
> Don't forget to check out the bottom notes for more info and questions you may have after reading. For now, just enjoy the story! Thanks for reading ♡

PROLOGUE  
PT.1 and PT.2

Now, it had been 13 years since the infamous death of Chara and Asriel, the beloved children of the Deemurr family, and many still mourned such a loss. Asgore was driven to the point of insanity, losing both his children over night. He made a new rule that applied to the whole of the Underground, that every human to fall down into this realm was to die. Be slaughtered. Toriel, enraged by her husband's poor choices, left for the other side of the Underground, leaving Ashore to rule alone. But things weren't entirely as you think. Chara’s soul was absorbed by Asriel right? But a human soul can live on after death… even after being absorbed by a monster soul incredibly so. Her soul drifted across the Undertale in boredom, you might think. But you’re wrong again. Her soul was pent up with rage, disgust, and revenge. She loved the monsters and they gave her something she did not have... a family. Love. So why…? She was angered by Asriel failing to complete their mission, after all they had been through. After EVERYTHING, he chose to give himself up and be a pacifist. To Chara, that was just idiocy. She wanted to show these monsters where kindness really got them. Sadness. Destruction. Pain. LOVE.

But she was weak. She was in no state to do such a thing. A bodiless, vengeful soul roaming around the Underground… seems like a joke. So, she fed off others who fell down into the Underground, specifically humans. A human soul can possess another, can occupy the vessel. Chara could feed off of the human vessel, become her human like form again by draining the wit, the power, the thing that allows a human to persist after death little by little, all without them even knowing it. For Chara, that is DETERMINATION. As said, it varies depending on what trait resembles the human the most. It… no… let’s call this SOUL POWER. But they were all useless. USELESS. They didn’t have enough soul power. Not enough to support her. But then… when the seventh human fell down 13 years after her death, she was greeted with something that maliciously made her soul pound.

Her name was Frisk. She was 5 years old when she fell down, yet more powerful than all the rest. Her SOUL POWER was incredibly strong, and she didn’t even know it. An innocent young child unaware of the dangers ahead. Chara instantly took this opportunity to possess her soul. Little Frisk was greeted by a flower named Flowey, and being her naïve little self, fell into his trap. What a fool she was to do such a thing, thought Chara. Flowey lured her in with kind and trustworthy words, only for her to be beat up relentlessly by his “bullets”. NO. He mustn’t kill her. Chara immediately subdued him with what little magic she had left, and played off as the hero. Frisk became extremely grateful. During this time of the week, Toriel would be walking through to see if anyone had fallen down, but it looked like she was a bit late this time. Chara knew all these things because over the past 13 years, she watched 6 humans walk through the Underground in an almost identical order. It was crazy, but she understood, for it would be come useful in the future…like a moment right now. She loomed over Frisk with a terrible smile spread across her face. It’s all out in front of her and all she needed to do was take it. So, she did.

She possessed Frisk’s soul in the blink of an eye. So painful, screams echoing throughout the dark and empty cave-like room as Frisk’s soul was penetrated by Chara’s. Pain… she was feeling pain again. So much that she could almost laugh. That’s when the screams stopped. Frisk… Chara fell to the ground, the process coming to an end, when Frisk’s eyes were no longer her’s... but the blood red of Chara’s. Blood dripped from the corner of her crooked smile, head slowly turning to face the dumbfound Flowey. She’d never possessed someone’s soul before. So much soul power… belonging to her.

“Oh my… a-are you alright?!” a voice came from the entrance, footsteps nearing the commotion. Flowey is blown the side once more, but with much more force.

The little five-year-old wipes the blood on the corner of her mouth with an eerily beaming smile. 

“Hey, mom.”

\------------------------------------------------------------------------------------------------------------------------------------------------

Pt.2

\------------------------------------------------------------------------------------------------------------------------------------------------

SCREAMING

CRYING

DEATH

PAIN

TEARS

BLOOD

DUST

KNIFE

Was all I could think of… nothing else would satisfy me. They know NOTHING. Naïve puppets only for me to control. I am the one in control. It was never you. Never you.

Never.

You.

\------------------------------------------------------------------------------------------------------------------------------------------------

It’s been a long battle. My clothes are stained with blood. Does he even understand what he's really doing?

...

Never mind that

It's time for this aimless battle to end. He'll never be able to defeat me. My lips curl and give a tiny laugh. 

“They aren’t dead.”

His eyes flicker blue as he eyes me curiously.

“But… how…”

“You don’t need to know how, just that they’re alive, and all you need to do is surrender. You’ll have them back again… even your brother.”

His eyes flare yet again, except even brighter. I’ve got his attention, but he won’t believe my lie. He may be stupid, but he isn’t dumb. Sure, I have them alive, but I’m only using them for bait. They’ll all die in the end regardless.

“That’s not true. I saw their dust all over town, and on YOUR hands,” he growls, getting impatient.

“Not their dust. The others. Everyone else is dead except them. The ones who truly matter to you.”

I sneer helplessly.

“But this isn’t really about you, is it? This is solely about what I’ve done, and what I’m going accomplish just by killing every single person on this useless planet. But I’ve done you a favor, now. So, you’ll have to repay me. I know you don’t believe they’re alive, so I’ll show them to you,” I say, a mischievous glint in my blood red eyes. I’ve always had that glint, but now it shines brighter than ever…  
Vines shoot out from the ground, the hall crumbling beneath such impact. They all rise from the ground, trapped in Flowey’s- or should I say Asriel’s- vines. Guess the little moron wasn’t as useless as I thought he’d be.

“Tee hee hee…” he giggles maliciously. A distorted smile spreads across his face as he wiggles his vines around, making his captives shake around aimlessly. What an idiot. A gullible brat.

My eyes widened and I started to smile. I guess I should tell him who he’s been talking to all along. I’ve been in this overly small vessel for a while. I’m powerful enough.  
“Oh, and I bet you’re wondering, how the hell did a little five-year-old create such a crime?” I laugh, licking the almost dried blood staining my fingers.  
“I have way more questions than that.” his voice shakes with rage. So easy to read, that little skeleton.  
I move tediously as a shadow crosses my eyes, making my eyes glow even brighter. I cock my head in another wide smile.

"This body's a bit tiny, dontcha think?" I drawled, shrugging my shoulders playfully.

Finally.  
It’s hard to describe the feeling I felt that day. Being ripped apart and put back my rightful place hurt more than I thought it to be, but I kept smiling. Finally clenching my own fists, moving my own legs, seeing through my own eyes… determination flows through me...  
He stumbles back in horror and glances at the withered and bloody body thrown to the side. The vessel. Frisk... was it? I don’t know how, but I could feel her soul’s presence. It was still in the body, almost dead. It won’t survive…  
I outstretch my hand to his.

“Surrender, and you, alongside your friends, will live.”  
His eyes dart from the captives squeezed between Asriel’s vines. His breath hitches in his throat for a moment.

…

Suddenly, razor-sharp bones splinter through my body yet again. I cough out blood and stare at him for a moment. It hurts more this time, considering I’m not using a vessel as a shield and body. I yank the bloodied bones out of my blatantly exposed stomach. So much… blood. The smell… I begin to smile. A ridiculous smile. His eye is aglow, flashes of piercing blue and yellow, echoing back and forth between his empty skull. Beads of sweat roll down his forehead a he readies another attack. Brainless twit. You chose wrong.  
“…I see. That’s how it is then?”  
Twitch, twitch, his fingers go.  
He repeats the same lines again.  
Again, except he actually means them.  
His voice shakes.  
“Like I said… It’s a beautiful day outside, eh? Birds are singing, flowers are blooming… On days like these, kids like you…”

“Should be burning in hell.”

\------------------------------------------------------------------------------------------------------------------------------------------------


	2. A Cool New Game

**Notes for the Chapter:**

> Hey hey! First chapter up!! I figured I should at least give some context as to what the whole shebang was about, and so I decided to put the first chapter up :) I hope you all enjoy! 
> 
> If you have any questions, leave them in the comments below, and let me know if you're enjoying everything so far by leaving me kudos!! Thanks for reading. Enjoy! ♡

Chapter 1

The sounds of the birds chirping and the smell of pie awoke the young child. Krista it was. A 12-year old firecracker, with nothing more than the world ahead of her it seemed. Her eyes opened wide, well not really. Let’s just say she had really squinty eyes. Almost cartoon like! She stretched, and yawned, her wavy, chocolate brown hair up in a messy bun. She’s always too lazy to dry her hair at night after she takes a shower, and when she wakes up, she never takes it out, and just redoes it to make it more secure. She dresses up quickly and hops downstairs after her mom’s delicious cooking.

“Good morning, dear. Did you brush your teeth this time?” her mother coons kindly.

“Of course, I did!” she says begrudgingly, folding her arms.

“Don’t give me that ‘of course’! I know you didn’t brush your teeth last night! You better have brushed really good.” she smirks playfully. She nods her head towards the plate of food sitting on the counter and Krista grabs it hastily. She snarfs it down heartily.

“Not so fast! Goodness, Krista, have some manners!” her mother scolds, glaring at her and shaking her head.

“Sorry mom! I don’t want to be late!” she says, already stuffing her bag with her homework. She yanks open the door, but as she’s about to head out…

“Kris! I love you! Have a good day at school!” her mom calls back. Krista turns her head and gives a heartwarming smile.

“Love ya too mom!” she calls back.

\----------------------------------------------------------------------------------------------------------------------------------------------

The bus zooms in front of the bus stop just in time. Krista clamors onto the bus greeting the bus driver merrily.

“Morning Mister Drake!”

“Hey Krista! ICE to see you as always.” he laughs, patting her on the back.

“It’s not even winter…that was a terrible pun.” she chuckles along awkwardly.

“Even worse than Sal’s?” he questions, raising his brows playfully. She giggles and gives a funny smile.

“Maybe not as bad a Sal’s.”

She trudges to the back of the bus and something catches her eye. Someone’s hands are waving frantically in the air. Two girls are sitting side by side, one with red hair and one with blonde.

“OVER HERE KRISSY!!!” shouts the red head.

“Not so loud, Tia!” whispers the blonde frantically. “You’re drawing too much attention…!” she flushes, tugging at her best friend’s sleeve.

“Hey gal pals!” Krista high-fives them both.

“Krissy, you won’t believe what’s going on!!” Unity shouts excitedly. “C’mon Al! TELL HER!” she continues, nudging her best friend. Krista waits eagerly for Allie to spill the news. Allie straightens up and clears her throat.

“W-well… there’s this really cool game that just came out, and everyone’s raving about how good it is, but I haven’t played it before… I heard it mentions anime quite a lot!!” she directs, as her eyes light up at the mention of anime. Surprisingly to both girls, Krista rolls her eyes.

“Ugh, is it another one of those pointless shooting games?” she mutters as she pulls out a book, digging her nose in it to hide her boredom. The girls exchange mischievous glances. Unity shoves her finger down into the inside rim of the book, revealing her face again.

“But it’s an RPG!!! Those kinds of game are super awesome!!” she roars throwing her hands in the air.

“Just try it, Krissy. You might like it! A-and it’s free to download, so that’s a plus,” she quietly encourages. Krista heaves a big sigh, shutting her book abruptly and stuffing it back inside her backpack.

“Fine then… I trust you girls, so I’ll try it after school today.” she mutters absentmindedly, busying herself with a bug on the window. She had never been huge on playing videogames, considering the thought that comes up when thinking about it; guns, killing, weird and revealing looking avatars, etc. She stumbled out of the stuffy bus along with the other kids. As she approached her locker inside, she ran through all her classes… Social Studies, Algebra, Language Ar-

Bump! Krista knocks herself into another classmate…

“H-HEY! Watch where you’re going!! The girl snaps, elbowing Krista out of the way, head down. But the way she did it was like she was hesitant. “S-sorry!” she fumbles, clutching her backpack tightly, as she walks away slowly. She could feel the girl’s lingering glare at her back as she opened her locker door hesitantly. “Geez, what’s that girl’s problem?” she thought quietly to herself. Looks like that girl is new, she’s never seen her before.

\----------------------------------------------------------------------------------------------------------------------------------------------

Another boring day at school, nothing special but the quiet ramblings of the new game, called ‘Undertale’. “It better not be one of those pointless gun games.” she grits her teeth for the last time, almost at the edge of insanity with all this talk about it. It was finally the end of the day, tired out of her wits, she clamored out of school along with many, many other students. Suddenly, a hand yanks her to the side, and pins her to the ground. Krista somehow finds herself face to face with the girl from earlier, an angered look plastered across her flushed face.

“H-how dare you! You really think you have the guts to steal from me?!” she yells, launching a fist into Krista’s stomach. After a couple times, she coughs up blood. 

“Get off of me! Wh- hey! S-Stop!!” she says confused as ever, voice shaking as she pushes herself off of her and onto her feet. Her hands are clenched tightly, nails digging into the palm of her hand.

“You stole it! Now give it back, asshole!!!” she says, shrilly. She lunges herself forward, her hands open. Krista takes the opportunity to grab her wrists, and pushes back grunting with effort. She peers around as onlookers laugh, or take videos with wild commentary.

“JERKS!! Why aren’t you doing anything?!” she shouts aimlessly into the now gathered audience.

“Fight, fight, fight!” they chant. Passers either turn away rolling their eyes, or join the riot, egging them on. Suddenly, someone is seen pushing through the crowd, clearly older than most of the kids there.

“Er, ‘scuse me kid, ya gotta move.”

“You want to pick a fight with me, old man?!”

“No, not really. Also, I’m not even that old.”

“Take a look in the mirror, ya old geezer!”

“Damn… I’d kill for a taco right now…”

“Wha-

“Oh sorry, I don’t really wanna TACO ‘bout it.”

“You ugly bastar-!”

“Move it, kid.”

A guy around 19 pushes his way through the crowd and stops right in front of the fight scene, where Krista is now seen on the ground again.

“Krista…? Hey… HEY! Break it up you two… I said break it up!!” the guy says, the two still going at it.

Krista does a double take on him for a moment before blurting out, “Sal?! What’re you doing here?”

“Yer mom told me she had some business to take care of and asked me to pick you up … but c’mon, what’s going on?” he asks, a little more calmly this time, placing his hands on her shoulders, his eyes running down her cuts and bruises. As she opens her mouth to talk, something catches her eye.

The girl… she’s crying. Fountains of tears run down her unscathed face. She notices Krista’s lingering gaze and hastily starts drying her tears with her sleeve.

Krista pushes herself away from Sal’s grip, walking toward her slowly.

“Hey… a-are you ok…?” she says quietly, placing a hand on her shoulder attentively. She flinches away from Krista’s touch, but her soothing voice made the girl cry even more, and began sobbing into her shoulder. Most of the crowd had dispersed, not wanting to witness a ‘sappy, crying mess’.

“D-did you really not take it? I looked everywhere for it!!” she cried through gasps and hiccups. Krista patted her back glancing back at Sal, who had the look of pure confusion, but also a sense of understanding. 

“Er… if you don’t mind me asking, what are you looking for?” she asks awkwardly as the girl rises from her now soaked sleeve. Krista doesn’t mind.

“Ah… well, I just transferred from another country a couple days ago, and I- I just lost my brother to a car accident. I, heh… have this picture of me and him,” she says lowering her eyes as she starts to tear up again. “I take it everywhere with me. I… guess I just assumed when you bumped into me, you took it. And for that, I’m really sorry… for that, and for what happened this morning. A lot of kids have been picking on me for a bit, so I thought maybe being a bit tougher, would get me through this…” she apologizes, her voice shaking roughly by now. Krista’s eyes widen and she pulls her in for a hug.

“I’m so sorry you’ve had to go through such things. Nobody should be bullied right when their trying to adjust to a new school. I’d be willing to help you look for that picture! I can see how important it is to you.” 

“Ha ha, wow… thank you…!” even after beating you up like that, you’d do that for me?

“That’s irrelevant,” Krista winks.

After some time, Krista and the girl, Harriet, talk things out, and eventually find the photo. It’s a run- down picture of a young Harriet on her brother’s back, laughing hysterically. Harriet practically leaps into her arms and thanks her profusely, along with many more apologies. 

“Oh! By the way, is that your brother? I guess that’s sort of the reason I started crying earlier… the way he talked to you and put his arms around you… really reminded me of my brother.” Harriet sighs, glancing at the photo tightly clutched in her hands. Krista’s face immediately heats up, Sal chuckling nervously behind them. When she says it like that, it almost sounds… pedophile-ish. 

“A-Ah! Ahehe… he’s not my brother, but we’ve known each other for so long it kinda feels like it!” she says tightening her clammy hands. Sal gives a short nod, his mouth spreading into a sour grin. Krista almost laughs, sputtering, but fake coughs it off. She knows exactly what he’s thinking. He does not want to be painted in such a light.

“Oh…! I’m sorry again for the accusations,” Harriet says quickly.

“Anyways, thank you again for helping me out. It really meant so much to me… you really have no idea.”

“No prob! I’m here anytime!” Krista says brightly, clasping her hands in hers, sealing the deal. They each wave goodbye and walk off toward their destinations.

Krista and Sal head over toward his car, shutting the doors and driving off. Sal scratches his almost stubble beard before shoving the car keys into the keyhole and twisting his wrist firmly. His electric blue eyes stand out against the setting sun, golden hour is approaching.

“Your mom’s gonna be pretty pissed- er…I mean mad when you get back.” he says, giving a short glance at her bruised cheek. She only chuckles.

“I’m pretty clumsy as it is, so even if I tell her I tripped over a rock, she’ll believe me.” Krista shrugs, sighing as she gingerly touches an abrasion on her knee.

“Even then she’ll be worried, kid. I know I’d be worried if Pete got himself beat up just like you did.” he looks off into the distance with a concerned look. He cares about his little brother too much.

“But, unfortunately… you _beat_ him to it.” he turns to her with his signature toothy grin. Krista laughs for a while, then realizes what a dark joke that was.

“Ya got a heart of gold, K. And you’re built strong and tough like a _Kristmas_ tree, ya know? But that doesn’t mean you should just go around an’ let people walk all over ya.” he directs, parking his car on the side of the road near his own house. He slams the door and lazily leans on the car and gestures her to her house a couple blocks away. Despite the terrible pun, he makes a point. Krista is very outgoing, but can never bring herself to hurt someone, just defend herself. She sighs walking towards her home, about to wave goodbye, when she realizes something.

“You’re not gonna drop me over at my house? It’s kinda far to walk, but not that far to drive…”

“Nah, too tired, too lazy,” he says closing his eyes, and pulling out his phone. “Like I said, built like a Kristmas tree, you can make it a couple more blocks.”he flops down on the grass, smirking even more now. Krista gives him an ‘are you serious’ kind of look, crossing her arms in disapproval.

“Oh, and you’re so lazy you can pull out your phone instead of driving for another two seconds?” she pokes, raising her brows.

“Nah… I’m texting my brother to come drag me inside.”

That’s it. She facepalms and gives and ‘UGHHH’ before stalking off towards her house.

“Better pick up the pace and move those long legs of yours, the sun’s going down!” he calls back to her just as his door swings open forcefully. A little boy about the age of six, but fairly tall pouts his lips and balls his fists shaking.

“Oh, heya bro. Ya get my text?” Sal cocks his head to get a better view of his fuming little brother.

“Not today, Sal! Someone as heroic as me has no obligation of dragging his lazy brother’s butt inside!” he crosses his arms and furrows his brow turning to stomp back inside.

“Oh ok, so no Power Rangers tonight?” his brother stops midway and suddenly comes bolting out, but composes himself before grabbing hold of his brother’s arms.

“F-fine! Just this last time.” he mumbles, clearly still fuming.

“Ayyyyeee that’s my bro.”

\----------------------------------------------------------------------------------------------------------------------------------------------

**Author's Note:**

>   
>  Here's that Q&A:
> 
> \- Is this a Frisk/Sans story?  
> No. Well, not really. I love the ship, but I decided the relationship wouldn't be appropriate for the theme of this story, but just think of their relationship to be fluffy and platonic, like an older brother and sister relationship :3
> 
> \- The prologue doesn't really seem to fit the summary of the story... where is this going?  
> The prologue is set there for you to take from later in the story. In the first chapter, I'll cover some more things like how the present day fits with all this and how they all just generically fit together. This is just a test to see if people like the plot.
> 
> \- What kind of AU is this? Like, the story mentions the Underground being a 'realm'. What's that all about?  
> So in this AU, the Underground is completely separate from the human world. When it says 'fell down' its implying the human 'fell' from a different world.
> 
> \--------------------------------------------------------------------------------------------------
> 
> If you have any other questions, please DM me on angelictrashcan on Instagram! Oh, also a follow is appreciated. :)
> 
> I also want to say thank you to my friend lockets who’s also on Ao3 and recently just released a BNHA fanfic called "Last Minute Stitches" for inspiring me to put this story out there. Btw, I’m her editor ;) Be sure to check her out!!
> 
> Thank you so much for reading, and if you enjoyed this Prologue, leave a kudo and comment below!!☆


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